Re: [PATCH v9 6/6] drm: renesas: rz-du: mipi_dsi: Add support for RZ/V2H(P) SoC

[Lad, Prabhakar]

Hi Geert,

Thank you for the review.

On Mon, Oct 6, 2025 at 1:49 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Prabhakar,
>
> On Thu, 2 Oct 2025 at 18:17, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> >
> > Add MIPI DSI support for the Renesas RZ/V2H(P) SoC. Compared to the
> > RZ/G2L family, the RZ/V2H(P) requires dedicated D-PHY PLL programming,
> > different clock configuration, and additional timing parameter handling.
> > The driver introduces lookup tables and helpers for D-PHY timings
> > (TCLK*, THS*, TLPX, and ULPS exit) as specified in the RZ/V2H(P) hardware
> > manual. ULPS exit timing depends on the LPCLK rate and is now handled
> > explicitly.
> >
> > The implementation also adds support for 16 bpp RGB format, updates the
> > clock setup path to use the RZ/V2H PLL divider limits, and provides new
> > .dphy_init, .dphy_conf_clks, and .dphy_startup_late_init callbacks to
> > match the RZ/V2H sequence.
> >
> > With these changes, the RZ/V2H(P) can operate the MIPI DSI interface in
> > compliance with its hardware specification while retaining support for
> > existing RZ/G2L platforms.
> >
> > Co-developed-by: Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>
> > Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > Reviewed-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
> > ---
> > v8->v9:
> > - Updated Kconfig to select CLK_RZV2H
> > - Updated to use renesas.h
> > - Added reviewed-by tag from Tomi
>
> Thanks for the update!
>
> > --- a/drivers/gpu/drm/renesas/rz-du/Kconfig
> > +++ b/drivers/gpu/drm/renesas/rz-du/Kconfig
> > @@ -19,6 +19,7 @@ config DRM_RZG2L_USE_MIPI_DSI
> >         depends on DRM_BRIDGE && OF
> >         depends on DRM_RZG2L_DU || COMPILE_TEST
> >         default DRM_RZG2L_DU
> > +       select CLK_RZV2H
>
> As the kernel test robot has already told you, this is not a good idea.
> RZ/V2H support is optional, just rely on (dummy) rzv2h_get_pll_*()
> helpers returning false if CLK_RZV2H is not enabled.
>
Agreed, I will add static inline helpers in renesas.h if !CLK_RZV2H.

Cheers,
Prabhakar

> >         help
> >           Enable support for the RZ/G2L Display Unit embedded MIPI DSI encoders.
> >
>
> Gr{oetje,eeting}s,
>
>                         Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
>